EN 50495:2010

Safety devices required for the safe functioning of equipment with respect to explosion risks

This European Standard specifies the requirements of electrical safety devices, which are used to avoid potential ignition sources of equipment in explosive atmospheres. This also includes safety devices, which are operated outside areas with explosive atmospheres, to guarantee the safe function of equipment with respect to explosion hazards. NOTE 1 This European Standard can also be used to design and assess safety devices for protective systems. Electrical equipment, which is intended for use in explosive atmospheres, may rely on the correct operation of safety devices which for example maintain certain characteristics of the equipment within acceptable limits. Examples of such safety devices are motor protection devices (to limit temperature rise during stall conditions) and controlling devices for pressurisation protection. By means of control or monitoring devices, sources of ignition can be avoided. Therefore these devices shall execute the appropriate measures in the appropriate reaction time, for example the initiation of an alarm or an automatic shut down. NOTE 2 Some potential ignition sources might not be controllable by safety devices, e.g. electrostatic discharges, ignition sparks caused by mechanical impact. Also some protection measures might not be controllable by safety devices, e.g. flameproof enclosures. Safety devices, whose safety function can not adequately be specified under the existing EN 60079 or EN 61241 series of standards, shall additionally be designed according to the requirements of this standard. Generally for complex safety devices appropriate design requirements are not provided in the existing types of protection (see 3.13 for the definition of a complex device). NOTE 3 In general the levels of safety required by this standard are considered to be equivalent to those provided by conformity to EN 60079-0 or EN 61241-0. No increase or decrease of safety is intended or required. Similarly neither increase nor decrease of safety with respect to EN 61508 series is intended. Safety devices can be classified in 2 types: a) devices, which are included as component in the equipment under control (see 3.8). The combined apparatus is considered as equipment. EXAMPLES - thermal switch or thermistor to avoid overheating, - temperature monitoring devices to control the surface temperature. b) devices, which are installed separately from the equipment under control and considered as associated apparatus exclusively for a specific type of protection or specific equipment under control. The combined apparatus is considered as a system. EXAMPLES - external control devices or safety related parts of a control system for type of protection pressurisation, - overload protective device for electric motors of type of protection Ex e ‘Increased Safety’, - control devices for battery charging equipment (protection against overcharging or deep discharging), - level detectors for the control of submersible pumps. Exclusions from this standard: Safety devices, where the safety function is adequately covered in the existing standards of EN 60079 and EN 61241 series do not need any additional assessment according to this standard. EXAMPLES Intrinsically safe associated apparatus, fuses, electromechanical overload protection, simple thermal protection devices (e.g. thermal fuses, thermal switches). The standard does not include devices or systems to prevent the occurrence of explosive atmospheres, e.g. inerting systems, ventilation in workplaces and containers/vessels. Gas detectors, which are covered under EN 61779 series, EN 50271 or EN 50402 are also excluded from the scope of this standard. This standard does not deal with protection by control of ignition source ‘b’ for non-electrical equipment as defined in EN 13463-6.

Sicherheitseinrichtungen für den sicheren Betrieb von Geräten im Hinblick auf Explosionsgefahren

Dispositifs de sécurité nécessaires pour le fonctionnement sûr d'un matériel vis-à-vis des risques d'explosion

Varnostne naprave, potrebne za varno obratovanje opreme glede tveganja eksplozije

Ta evropski standard opredeljuje zahteve električnih varnostnih naprav,ki se uporabljajo za izogibanje možnim virom vžiga opreme v eksplozivnih atmosferah. To vključuje tudi varnostne naprave, s katerimi se upravlja zunaj področij z eksplozivno atmosfero, za zagotavljanje varnega obratovanja opreme glede tveganja eksplozije.

General Information

• Status: Published
• Publication Date: 25-Feb-2010
• Withdrawal Date: 30-Nov-2012
• ICS: 13.230 - Explosion protection
• ICS: 29.260.01 - Electrical equipment for working in special conditions in general
• ICS: 29.260.20 - Electrical apparatus for explosive atmospheres
• Technical Committee: CLC/TC 31 - Electrical apparatus for explosive atmospheres - General requirements
• Drafting Committee: CLC/TC 31 - Electrical apparatus for explosive atmospheres - General requirements
• Parallel Committee: IEC/TC 31 - Electrical apparatus for potentially explosive atmospheres
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Completion Date: 27-Jan-2021
• Directive: 2014/34/EU - Directive 2014/34/EU Of The European Parliament And Of The Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres (recast)
• Directive: 94/9/EC - Directive 94/9/EC of the European Parliament and the Council of 23 March 1994 on the approximation of the laws of the Member States concerning equipment and protective systems intended for use in potentially explosive atmospheres
• Ref Project: SIST EN 50495:2010 - Safety devices required for the safe functioning of equipment with respect to explosion risks

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 50495:2010
01-junij-2010
Varnostne naprave, potrebne za varno obratovanje opreme glede tveganja
eksplozije
Safety devices required for the safe functioning of equipment with respect to explosion
risks
Sicherheitseinrichtungen für den sicheren Betrieb von Geräten im Hinblick auf
Explosionsgefahren
Dispositifs de sécurité nécessaires pour le fonctionnement sûr d'un matériel vis-à-vis des
risques d'explosion
Ta slovenski standard je istoveten z: EN 50495:2010
ICS:
13.230 Varstvo pred eksplozijo Explosion protection
29.260.20 (OHNWULþQLDSDUDWL]D Electrical apparatus for
HNVSOR]LYQDR]UDþMD explosive atmospheres
SIST EN 50495:2010 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 50495:2010

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SIST EN 50495:2010

EUROPEAN STANDARD
EN 50495

NORME EUROPÉENNE
February 2010
EUROPÄISCHE NORM

ICS 13.230; 29.260.30


English version


Safety devices required for the safe functioning of equipment
with respect to explosion risks



Dispositifs de sécurité nécessaires  Sicherheitseinrichtungen
pour le fonctionnement sûr d'un matériel für den sicheren Betrieb von Geräten
vis-à-vis des risques d'explosion im Hinblick auf Explosionsgefahren





This European Standard was approved by CENELEC on 2009-12-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: Avenue Marnix 17, B - 1000 Brussels


© 2010 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50495:2010 E

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SIST EN 50495:2010
EN 50495:2010 – 2 –
Foreword
This European Standard was prepared by the Technical Committee CENELEC TC 31, Electrical apparatus
for potentially explosive atmospheres. The text of the draft was submitted to the formal vote and was
approved by CENELEC as EN 50495 on 2009-12-01.
This European Standard is to be read in conjunction with the European Standards for the specific types of
protection listed in EN 60079 or EN 61241 series of standards.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent rights.
The following dates were fixed:
– latest date by which the EN has to be implemented

at national level by publication of an identical

national standard or by endorsement
(dop) 2010-12-01
– latest date by which the national standards conflicting

with the EN have to be withdrawn
(dow) 2012-12-01
This European Standard has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and covers essential requirements of EC Directive
94/9/EC. See Annex ZZ.
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SIST EN 50495:2010
– 3 – EN 50495:2010
Contents
Introduction . 4
1 Scope . 5
2 Normative references . 6
3 Terms and definitions . 7
4 Ignition prevention by safety devices .
...